Hydroisomerization catalyst manufactured using a high nanopore volume alumina supports
09616419 ยท 2017-04-11
Assignee
Inventors
- Yihua Zhang (Albany, CA)
- Kamala Raghunathan Krishna (Danville, CA, US)
- Guan-Dao Lei (Walnut Creek, CA)
- Theodorus Ludovicus Michael Maesen (Moraga, CA)
Cpc classification
C10G45/64
CHEMISTRY; METALLURGY
B01J29/7492
PERFORMING OPERATIONS; TRANSPORTING
B01J35/00
PERFORMING OPERATIONS; TRANSPORTING
B01J29/00
PERFORMING OPERATIONS; TRANSPORTING
International classification
B01J35/00
PERFORMING OPERATIONS; TRANSPORTING
C10G45/64
CHEMISTRY; METALLURGY
Abstract
The present invention is directed to an improved finished hydroisomerization catalyst manufactured from a first high nanopore volume (HNPV) alumina and a pore size distribution characterized by a full width at half-maximum, normalized to pore volume, of 15 to 25 nm.Math.g/cc, and a second HNPV alumina having a pore size distribution characterized by a full width at half-maximum, normalized to pore volume, of 5 to 15 nm.Math.g/cc. Their combination yields a HNPV base extrudate having a low particle density as compared to a conventional base extrudates.
Claims
1. A hydroisomerization catalyst, comprising: a base extrudate comprising at least one molecular sieve selective towards isomerization of n-paraffins, a first alumina having a pore size distribution characterized by a full width at half-maximum, normalized to pore volume, of 15 to 25 nm.Math.g/cc, and a second alumina having a pore size distribution characterized by a full width at half-maximum, normalized to pore volume, of 5 to 15 nm.Math.g/cc; the catalyst further comprising at least one metal selected from the group consisting of elements from Group 6 and Groups 8 through 10 of the Periodic Table.
2. The hydroisomerization catalyst of claim 1, wherein the first alumina has a nanopore volume in the 2 nm to 50 nm range of 0.7 to 2 cc/g.
3. The hydroisomerization catalyst of claim 2, wherein the second alumina has a nanopore volume in the 2 nm to 50 nm range of 0.7 to 2 cc/g.
4. The hydroisomerization catalyst of claim 1, wherein the second alumina has a nanopore volume in the 2 nm to 50 nm range of 0.7 to 2 cc/g.
5. The hydroisomerization catalyst of claim 1, wherein a pore size distribution plot for the base extrudate will indicate a maximum peak with a shoulder located at a pore size between 7 and 14 nm.
6. The hydroisomerization catalyst of claim 1, wherein the base extrudate has a nanopore volume in the 6 nm to 11 nm range of 0.25 to 0.4 cc/g, a nanopore volume in the 11 nm to 20 nm range of 0.1 to 0.3 cc/g, and a nanopore volume in the 20 nm to 50 nm range of 0.04 to 0.1 cc/g.
7. The hydroisomerization catalyst of claim 1, wherein the base extrudate has a total nanopore volume in the 2 nm to 50 nm range of 0.7 to 1.2 cc/g.
8. The hydroisomerization catalyst of claim 1, wherein the base extrudate has a nanopore volume in the 6 nm to 11 nm range of 0.25 to 0.4 cc/g.
9. The hydroisomerization catalyst of claim 1, wherein the base extrudate has a particle density of 0.75 to 0.95 g/cc.
10. A process for hydroisomerization a hydrocarbonaceous feedstock, comprising contacting the feedstock with a hydroisomerization catalyst under hydroisomerization conditions to produce a hydroisomerized effluent; the hydroisomerization catalyst comprising a base extrudate comprising at least one molecular sieve selective towards isomerization of n-paraffins, a first alumina having a pore size distribution characterized by a full width at half-maximum, normalized to pore volume, of 15 to 25 nm.Math.g/cc, and a second alumina having a pore size distribution characterized by a full width at half-maximum, normalized to pore volume, of 5 to 15 nm.Math.g/cc; the catalyst further comprising at least one metal selected from the group consisting of elements from Group 6 and Groups 8 through 10 of the Periodic Table.
11. The process of claim 10, wherein the first alumina has a nanopore volume in the 2 nm to 50 nm range of 0.7 to 2 cc/g.
12. The process of claim 11, wherein the second alumina has a nanopore volume in the 2 nm to 50 nm range of 0.7 to 2 cc/g.
13. The process of claim 10, wherein the second alumina has a nanopore volume in the 2 nm to 50 nm range of 0.7 to 2 cc/g.
14. The process of claim 10, wherein a pore size distribution plot for the base extrudate will indicate a maximum peak with a shoulder located at a pore size between 7 and 14 nm.
15. The process of claim 10, wherein the base extrudate has a nanopore volume in the 6 nm to 11 nm range of 0.25 to 0.4 cc/g, a nanopore volume in the 11 nm to 20 nm range of 0.1 to 0.3 cc/g, and a nanopore volume in the 20 nm to 50 nm range of 0.04 to 0.1 cc/g.
16. The process of claim 10, wherein the base extrudate has a total nanopore volume in the 2 nm to 50 nm range of 0.7 to 1.2 cc/g.
17. The process of claim 10, wherein the base extrudate has a nanopore volume in the 6 nm to 11 nm range of 0.25 to 0.4 cc/g.
18. The process of claim 10, wherein the base extrudate has a particle density of 0.75 to 0.95 g/cc.
19. The hydroisomerization catalyst of claim 1, wherein the base extrudate has a bimodal pore size distribution.
20. The process of claim 10, wherein the base extrudate has a bimodal pore size distribution.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1)
(2)
(3)
(4)
DETAILED DESCRIPTION OF THE INVENTION
(5) Introduction
(6) Periodic Table refers to the version of IUPAC Periodic Table of the Elements dated Jun. 22, 2007, and the numbering scheme for the Periodic Table Groups is as described in Chemical and Engineering News, 63(5), 27 (1985).
(7) Hydroprocessing or hydroconversion refers to a process in which a carbonaceous feedstock is brought into contact with hydrogen and a catalyst, at a higher temperature and pressure, for the purpose of removing undesirable impurities and/or converting the feedstock to a desired product. Such processes include, but not limited to, methanation, water gas shift reactions, hydrogenation, hydrotreating, hydrodesulphurization, hydrodenitrogenation, hydrodemetallation, hydrodearomatization, hydroisomerization, hydrodewaxing and hydroisomerization including selective hydroisomerization. Depending on the type of hydroprocessing and the reaction conditions, the products of hydroprocessing can show improved physical properties such as improved viscosities, viscosity indices, saturates content, low temperature properties, volatilities and depolarization.
(8) Hydroisomerization refers to a process in which hydrogenation and accompanies the isomerization of n-paraffinic hydrocarbons into their branched counterparts.
(9) Hydrocarbonaceous means a compound or substance that contains hydrogen and carbon atoms, but which can include heteroatoms such as oxygen, sulfur or nitrogen.
(10) Lube oil, base oil and lubricating base oil are synonymous.
(11) LHSV means liquid hourly space velocity.
(12) SCF/BBL (or scf/bbl, or scfb or SCFB) refers to a unit of standard cubic foot of gas (N.sub.2, H.sub.2, etc.) per barrel of hydrocarbon feed.
(13) Nanopore means pores having a diameter between 2 nm and 50 nm, inclusive.
(14) Where permitted, all publications, patents and patent applications cited in this application are herein incorporated by reference in their entirety; to the extent such disclosure is not inconsistent with the present invention.
(15) Unless otherwise specified, the recitation of a genus of elements, materials or other components, from which an individual component or mixture of components can be selected, is intended to include all possible sub-generic combinations of the listed components and mixtures thereof. Also, include and its variants are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other like items that may also be useful in the materials, compositions and methods of this invention.
(16) All numerical ranges stated herein are inclusive of the lower and upper values stated for the range, unless stated otherwise.
(17) Properties for materials described herein are determined as follows:
(18) (a) Surface area: determined by N.sub.2 adsorption at its boiling temperature. BET surface area is calculated by the 5-point method at P/P.sub.0=0.050, 0.088, 0.125, 0.163, and 0.200. Samples are first pre-treated at 400 C. for 6 hours in the presence of flowing, dry N.sub.2 so as to eliminate any adsorbed volatiles like water or organics.
(19) (b) Nanopore diameter and volume: determined by N.sub.2 adsorption at its boiling temperature and calculated from N.sub.2 isotherms by the BJH method described in E. P. Barrett, L. G. Joyner and P. P. Halenda, The determination of pore volume and area distributions in porous substances. I. Computations from nitrogen isotherms. J. Am. Chem. Soc. 73, 373-380, 1951. Samples are first pre-treated at 400 C. for 6 hours in the presence of flowing, dry N.sub.2 so as to eliminate any adsorbed volatiles like water or organics.
(20) (c) API gravity: the gravity of a petroleum feedstock/product relative to water, as determined by ASTM D4052-11.
(21) (d) Polycyclic index (PCI): as measured by ASTM D6397-11.
(22) (e) Viscosity index (VI): an empirical, unit-less number indicated the effect of temperature change on the kinematic viscosity of the oil. The higher the VI of a base oil, the lower its tendency to change viscosity with temperature. Determined by ASTM 2270-04.
(23) (f) Viscosity: a measure of fluid's resistance to flow as determined by ASTM D445.
(24) (g) Water pore volume: a test method to determine the amount of water that a gram of catalyst can hold in its pores. Weigh out 5-10 grams of sample (or amount specified by the engineer) in a 150 ml. beaker (plastic). Add deionized water enough to cover the sample. Allow to soak for 1 hour. After 1 hour, decant the liquid until most of the water has been removed and get rid of excess water by allowing a paper towel absorb the excess water. Change paper towel until there is no visible droplets on the walls of the plastic beaker. Weigh the beaker with sample. Calculate the Pore volume as follows:
FI=W* F=final weight of sample I=initial weight of sample W*=weight or volume of water in the sample PV=W*/I (unit is cc/gm)
(25) (h) Particle density: Particle density is obtained by applying the formula D=M/V. M is the weight and V is the volume of the catalyst sample. The volume is determined by measuring volume displacement by submersing the sample into mercury under 28 mm Hg vacuum.
(26) Hydroisomerization Catalyst Composition
(27) The present invention is directed to an improved finished hydroisomerization catalyst manufactured from a high nanopore volume (HNPV) base extrudate. The HNPV base extrudate is manufactured from (1) a first high HNPV alumina having a broad pore size distribution (BPSD), (2) a second HNPV alumina having narrow pore size distribution (NPSD), and (3) a molecular sieve that is selective towards the isomerization of n-paraffins.
(28) The composition of the finished catalyst, based on the bulk dry weight of the finished hydroisomerization catalyst, is described in Table 1 below.
(29) TABLE-US-00001 TABLE 1 1.sup.st HNPV alumina support (BPSD) 5-55 wt. % 2.sup.nd HNPV alumina support (NPSD) 5-55 wt. % total molecular sieve content 25-85 wt. % total active metal content 0.1-1.0 wt. % total promoter content 0-10 wt. %
(30) For each embodiment described herein, the first HNPV alumina component is characterized as broad pore size distribution (BPSD), as compared to an alumina base used in conventional hydroisomerization catalysts.
(31) The HNPV, BPSD alumina used in the manufacture the finished hydroisomerization catalyst described herein have a PSD characterized by a full width at half-maximum (FWHM, normalized to pore volume) of 15 to 25 nm.Math.g/cc, and a NPV (2 nm-50 nm) of 0.7 to 2 cc/g.
(32) The HNPV, NPSD alumina used in the manufacture the finished hydroisomerization catalyst described herein has a full width at half-maximum (FWHM, normalized to pore volume) of 5 to 15 nm.Math.g/cc and a NPV (2-50 nm) of 0.7 to 2 cc/g.
(33) The HNPV alumina support components used in the hydroisomerization catalysts of the present invention, and base extrudates formed from these components, are characterized as having the properties described in Tables 2 and 3 below, respectively.
(34) TABLE-US-00002 TABLE 2 1.sup.st HNPV alumina 2.sup.nd HNPV alumina support (BPSD) support (NPSD) d10 (nm) 40-70 60-90 d50 (nm) 90-110 130-160 d90 (nm) 240-260 190-220 Peak Pore Diameter () 50-70 140-200 NPV - 6 nm-11 nm (cc/g) 0.2-0.3 0.1-0.3 NPV - 11 nm-25 nm (cc/g) 0.15-0.35 0.35-0.65 NPV - 25 nm-50 nm (cc/g) 0.05-0.15 0.05-0.15 Total NPV (2-50 nm) (cc/g) 0.7-2 0.7-2 BET surface area (m.sup.2/g) 300-400 200-300
(35) TABLE-US-00003 TABLE 3 HNPV Base Extrudate d10 (nm) 30-50 d50 (nm) 80-100 d90 (nm) 180-200 Peak Pore Diameter () 110-130 NPV - 6 nm-11 nm (cc/g) 0.25-0.4 NPV - 11 nm-20 nm (cc/g) 0.1-0.3 NPV - 20 nm-50 nm (cc/g) 0.04-0.1 Total NPV (2-50 nm) (cc/g) 0.7-1.2 BET surface area (m.sup.2/g) 250-350 WPV (water pore volume) (g/cc) 0.6-1.0 particle density (g/cc) 0.75-0.95
(36) The HNPV alumina supports are combined with the molecular sieve to form a HNPV base extrudate having a bimodal PSD suitable for hydroisomerizing n-paraffins while minimizing the conversion of the hydrocarbon molecules to fuels. A pore size distribution plot for the bimodal PSD HNPV base will indicate a maximum peak with a shoulder located at a pore size between 7 and 14 nm.
(37) The improvement in porosity of the hydroisomerization catalyst favors minimizing the formation of hydroisomerization transition species by lowering the residence time and by increasing the sweeping efficiency, thus decreases the probability of hydrocracking. This leads to the enhancement in the hydroisomerization selectivity.
(38) Finished hydroisomerization catalysts manufactured using the bimodal PSD HNPV base extrudate of the present invention exhibit improved hydrogen efficiency, and greater product yield and quality as compared to conventional hydroisomerization catalysts containing pure conventional alumina components.
(39) For each embodiment described herein, the amount of the HNPV, BPSD alumina component in the finished hydroisomerization catalyst is from 10 wt. % to 60 wt. % based on the bulk dry weight of the hydroisomerization catalyst. In one subembodiment, the amount of the HNPV, BPSD alumina component in the hydroisomerization catalyst is from 20 wt. % to 40 wt. % based on the bulk dry weight of the finished hydroisomerization catalyst.
(40) For each embodiment described herein, the amount of the HNPV, NPSD alumina component in the finished hydroisomerization catalyst is from 10 wt. % to 60 wt. % based on the bulk dry weight of the hydroisomerization catalyst. In one subembodiment, the amount of the HNPV, NPSD alumina component in the hydroisomerization catalyst is from 10 wt. % to 30 wt. % based on the bulk dry weight of the finished hydroisomerization catalyst.
(41) For each embodiment described herein, the hydroisomerization catalyst contains one or more medium pore molecular sieves selected from the group consisting of MFI, MEL, TON, MTT, *MRE, FER, AEL and EUO-type molecular sieves, and mixtures thereof.
(42) In one subembodiment, the molecular sieve is selected from the group consisting of SSZ-32, small crystal SSZ-32, ZSM-23, ZSM-48, MCM-22, ZSM-5, ZSM-12, ZSM-22, ZSM-35 and MCM-68-type molecular sieves, and mixtures thereof.
(43) In one subembodiment, the one or more molecular sieves selected from the group consisting of molecular sieves having a *MRE framework topology, molecular sieves having a MTT framework topology, and mixtures thereof.
(44) The amount of molecular sieve material in the finished hydroisomerization catalyst is from 20 wt. % to 80 wt. % based on the bulk dry weight of the hydroisomerization catalyst. In one subembodiment, the amount of molecular sieve material in the finished hydroisomerization catalyst is from 30 wt. % to 70 wt. %.
(45) As described herein above, the finished hydroisomerization catalyst of the present invention contains one or more hydrogenation metals. For each embodiment described herein, each metal employed is selected from the group consisting of elements from Groups 8 through 10 of the Periodic Table, and mixtures thereof. In one subembodiment, each metal is selected from the group consisting of platinum (Pt), palladium (Pd), and mixtures thereof.
(46) The total amount of metal oxide material in the finished hydroisomerization catalyst is from 0.1 wt. % to 1.5 wt. % based on the bulk dry weight of the hydroisomerization catalyst. In one subembodiment, the hydroisomerization catalyst contains from 0.3 wt. % to 1.2 wt. % of platinum oxide based on the bulk dry weight of the hydroisomerization catalyst.
(47) The finished hydroisomerization catalyst of the present invention may contain one or more promoters selected from the group consisting of magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), potassium (K), lanthanum (La), praseodymium (Pr), neodymium (Nd), chromium (Cr), and mixtures thereof. The amount of promoter in the hydroisomerization catalyst is from 0 wt. % to 10 wt. % based on the bulk dry weight of the hydroisomerization catalyst. In an embodiment, a catalyst of the present invention contains from 0.5 to about 3.5 wt % of Mg. While not being bound by theory, such metals may effectively reduce the number of acid sites on the molecular sieve of the metal-modified hydroisomerization catalyst, thereby increasing the catalyst's selectivity for isomerization of n-paraffins in the feed.
(48) Hydroisomerization Catalyst Preparation
(49) In general, the hydroisomerization catalyst of the present invention is prepared by: (a) mixing and pepertizing the 1.sup.st and 2.sup.nd alumina supports with at least one molecular sieve to make an extrudate base; (b) impregnate the base with a metal impregnation solution containing at least one metal; and (c) post-treating the extrudates, including subjecting the metal-loaded extrudates to drying and calcination.
(50) Prior to impregnation, the extrudate base is dried at temperature between 90 C. and 150 C. (194 F.-302 F.) for 1-12 hours, followed by calcination at one or more temperatures between 199 C. and 593 C. (390 F.-1100 F.).
(51) The impregnation solution is made by dissolving metal precursors in deionized water. The concentration of the solution was determined by the pore volume of the support and metal loading. During a typical impregnation, the support is exposed to the impregnation solution for 0.1-10 hours. After soaking for another 0.1-10 hours, the catalyst is dried at one or more temperatures in the range of 38 C.-149 C. (100 F.-300 F.) for 0.1-10 hours. The catalyst is further calcined at one or more temperatures in the range of 316 C.-649 C. (600 F.-1200 F.), with the presence of sufficient air flow, for 0.1-10 hours.
(52) Hydroisomerization Overview
(53) As noted above, the finished hydroisomerization catalysts employing using the novel combination of the alumina components exhibit improved hydrogen efficiency, and greater product yield and quality as compared to conventional hydroisomerization catalysts containing conventional alumina components. This unique combination of the alumina supports provides for a finished hydroisomerization catalyst that is particularly suited for hydroprocessing disadvantaged feedstocks.
(54) Depending on the feedstock, target product slate and amount of available hydrogen, the catalyst of the present invention can be used alone or in combination with other conventional hydroisomerization catalysts.
(55) Finished hydroisomerization catalysts and catalysts systems useful with the finished hydroisomerization catalysts of the present invention are disclosed in U.S. Pat. Nos. 8,617,387 and 8,475,648, and U.S. Publication No. US 2011-0315598 A1.
(56) The following examples will serve to illustrate, but not limit this invention.
EXAMPLE 1
Preparation of Catalysts 1, 2 and 3
(57) Conventional catalyst 1 was prepared using 55 wt. % pseudo-boehmite alumina according to the method disclosed in U.S. Pat. No. 8,790,507 B2 to Krishna et al., granted on Jul. 29, 2014. The dried and calcined extrudate was impregnated with a solution containing platinum. The overall platinum loading was 0.325 wt. %.
(58) Catalyst 2 was prepared as described for conventional catalyst 1 by partially replacing the conventional alumina with a 37.5 wt. % HNPV alumina powder having a broad pore size distribution (BPSD). The properties of the BPSD HNPV alumina are described in Table 5 below.
(59) Catalyst 3 was prepared as described for conventional catalyst 1 except that conventional alumina was not used, and instead 20 wt. % of a HNPV alumina having a narrow pore size distribution (NPSD) and 35 wt. % of a HNPV alumina having a BPSD were used as the binding material. The properties of the NPSD HNPV alumina are described in Table 5 below.
(60) The composition of the three catalysts is described in Table 4 below.
(61) TABLE-US-00004 TABLE 4 conventional catalyst 1 catalyst 2 catalyst 3 conventional alumina 55% 17.5% HNPV NPSD alumina 20% HNPV BPSD alumina 37.5% 35% SSZ-32x 45% 45% 45%
(62) The pore properties of the binding materials (aluminas) are described in Table 5 below.
(63) TABLE-US-00005 TABLE 5 conventional HNPV BPSD HNPV NPSD Alumina alumina alumina alumina D.sub.50, (2-50 nm) 67 99 147 FWHM, 32 157 77 Pore Volume, 0.55 0.71 0.87 cc/g (2-50 nm)
(64) The pore properties of the catalyst base (extruded and calcined zeolite and aluminas) are described in Table 6 below.
(65) TABLE-US-00006 TABLE 6 conventional Base Extrudate catalyst 1 catalyst 2 catalyst 3 D.sub.50, (2-50 nm) 66 81 93 FWHM, 47 88 91 Pore Volume, cc/g (2-50 nm) 0.6 0.78 0.81 PV, % 0 30 35
(66) Additional pore properties of the aluminas are described in Table 7 below.
(67) TABLE-US-00007 TABLE 7 conventional HNPV BPSD HNPV NPSD Alumina alumina alumina alumina d10 (nm) 38 51 69 d50 (nm) 67 97 147 d90 (nm) 96 258 201 Peak Pore Diameter () 73 61 167 NPV - 6 nm-11 nm 0.33 0.26 0.18 (cc/g) NPV - 11 nm-20 nm 0.03 0.19 0.54 (cc/g) NPV - 20 nm-50 nm 0 0.12 0.09 (cc/g) Total NPV (2-50 nm) 0.55 0.71 0.87 (cc/g) BET surface area (m.sup.2/g) 296 380 226
(68) Additional pore properties of the base extrudates are described in Table 8 below. A plot of the pore size distributions is illustrated in
(69) TABLE-US-00008 TABLE 8 conventional Base Extrudate catalyst 1 catalyst 2 catalyst 3 d10 (nm) 38 43 43 d50 (nm) 66 81 93 d90 (nm) 190 150 184 Peak Pore Diameter () 67 101 113 NPV - 6 nm-11 nm (cc/g) 0.23 0.36 0.31 NPV - 11 nm-20 nm (cc/g) 0.07 0.15 0.23 NPV - 20 nm-50 nm (cc/g) 0.05 0.04 0.07 Total NPV (2-50 nm) (cc/g) 0.60 0.78 0.81 BET surface area (m.sup.2/g) 314 339 314 WPV, (g/cc) 0.58 0.67 0.77 particle density (g/cc) 0.95 0.91 0.89
EXAMPLE 2
Hydroisomerization Performance
(70) Catalysts 1, 2 and 3 were used to hydroisomerize a light neutral vacuum gas oil (VGO) hydrocrackate feedstock having the properties outlined in Table 9 below.
(71) TABLE-US-00009 TABLE 9 Feedstock Properties gravity, API 34 S, wt % 6 viscosity index at 100 C. (cSt) 3.92 viscosity index at 70 C. (cSt) 7.31 wax, wt % 12.9 DWO VI 101 DWO Vis@100 C., cSt 4.08 DWO Vis@40 C., cSt 20.1 Distillation Temperature (wt %), F. ( C.) 0.5 536 (280) 5 639 (337) 10 674 (357) 30 735 (391) 50 769 (409) 70 801 (427) 90 849 (454) 95 871 (466) 99.5 910 (488)
(72) The reaction was performed in a micro unit equipped with two fix bed reactor. The run was operated under 2100 psig total pressure. Prior to the introduction of feed, the catalysts were activated by a standard reduction procedure. The feed was passed through the hydroisomerization reactor at a liquid hour space velocity (LHSV) of 2, and then was hydrofinished in the 2nd reactor as described in U.S. Pat. No. 8,790,507B2, which was loaded with a Pd/Pt catalyst to further improve the lube product quality. The hydrogen to oil ratio was about 3000 scfb. The lube product was separated from fuels through the distillation section.
(73) Pour point, cloud point, viscosity, viscosity index and simdist were collected on the products.
(74) Table 10 below describes the lube oil product yield for the three catalysts.
(75) TABLE-US-00010 TABLE 10 conventional Catalyst catalyst 1 catalyst 2 catalyst 3 Yield of lube product, wt % Base +0.9 +1.4
(76)
(77) Compared to catalyst 1, catalyst 2 gained about 1 wt. % lube product. Catalyst 3 generated 1.4 wt. % more lube product. Both catalysts 2 and 3 have higher nanopore volume and larger nanopore size. Combined with a bimodal pore size distribution, catalysts 2 and 3 generated less fuels and gas. Regarding the activity, both Catalyst 1 and 3 were about 10 F. more active than Catalyst 2.
(78) While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.